"Mine's in with the spare parts," Rick said.

Scotty took his flashlight and leveled it at a pack yak who carried boxes of rations. "I'll put it in with this bunch of chow," he decided. "Then I'll know where it is."

"You always know where the food is," Rick jibed. He unrolled the fleece-lined sleeping bag and unzipped it. It was army type, and equipped with an extra cover that could be propped up like a tent in bad weather. No matter how cold it might get they would sleep warmly.

Fires were springing up. The bearers were getting ready to eat. They had brought their own rations, mutton mostly, and bricks of tea. Their water was carried in skins, while the white men had brought canned water from the States in their ration crates.

Sahmeed saw to it that a fire was lit for the scientists and the boys. It burned with a low blue flame, due to some peculiarity of the wood. Bundles of it had been brought along on two of the mules.

Scotty tore open one of the big ration cases and said, "Bacon and eggs tonight. With fruitcake for dessert. Also coffee." He produced the items as he named them.

The ground-up bacon and powdered eggs tasted good, and they ate with appet.i.te, while the bearers squatted over their meals of mutton, boiled rice, and tea.

After the meal, the professors retired at once to their sleeping bags, but Rick and Scotty walked back along the trail and looked at the stars that seemed to press close with icy clearness.

"We're on the roof of the world," Rick said.

"But the stars look the same. There's the Big Dipper."

The constellation was like an old friend, overhead. They watched the stars in silence for a few moments, then went back to their sleeping bags and climbed in.

There was no sound, no cry of bird or beast, and for a moment the very silence kept them awake - but only for a moment.

When dawn came it was suddenly, like a huge light being switched on. The boys awakened to the sound of the bearers preparing the morning meal and to the stomping of the pack animals. They s.h.i.+vered as they crawled from the warm sleeping bags.

The professors were already up, and the aroma of hot tea sharpened their appet.i.tes. There were hamburger cakes for breakfast, taken from the big ration boxes, and crackers and a fruit bar.

While the bearers packed the animals, they stood at the edge of the trail, looking down into a gorge that vanished in the morning mist over a trackless valley far below.

Soon the wooden rods of the bearers slapped against tough hide and the animals started their ponderous progress. Sahmeed took his place at the head of the caravan. The boys and the professors fell in behind, and the procession moved on.

It was shortly after this dawn start that Rick pulled up beside Scotty and said, "I thought you were in condition, Sarge."

"So did I," answered Scotty, who was breathing heavily. Then he grinned. "And stop holding your breath so you won't puff, you faker!"

Rick took a deep breath but he couldn't seem to get enough air into his lungs.

"It's the alt.i.tude," Scotty told him. "Professor Zircon says we're seven thousand feet up."

Rick whistled.

"And going higher," Scotty added.

Rick looked at the mountains that mounted like stairs before them. "What we need is my Piper Cub."

"Your little baby would never make it over those," Scotty said, pointing at the snow-clad peaks.

Proud as he was of his little plane back on Spindrift Island, Rick had to admit that Scotty was right. His thoughts were beginning to turn toward home when he heard a commotion from the front of the caravan.

"Looks like Zircon and Sahmeed are having a confab," Scotty remarked.

They walked to the side of the two men. As they reached them, Rick heard Zircon ask, "Does this ridiculous path correspond to this line on the map?"

Rick looked toward the path at which Zircon was pointing. It did seem ridiculous that they should turn off this fairly good road onto the narrow, winding path to the left.

Sahmeed, however, was shaking his head in a violent affirmative.

"Tengi-Bu wait there," he said.

Zircon checked the map again.

"Well, the map makers who charted this should know," he muttered. "But it does seem to be doing it the hard way." He folded the map, returned it to his case, and motioned to Sahmeed to carry on.

In the coolness of the mountains, the sun seemed to race on its journey from one horizon to the next, and before he knew it, Rick had counted three such trips by Old Sol.

"Three days. I'm beginning to get used to this thinner atmosphere," Rick told Scotty.

"Me, too. I wish the scenery would change, though."

"That's what you said about India," Rick joked. "Relax. Why, people pay big money for vacations in the mountains."

"Who's kicking?" Scotty answered in a preoccupied way, looking at something far off to his left.

"What are you staring at?" Rick asked.

"A sheepherder ... I guess." Scotty pointed toward a high cleft in the mountain behind them. "It looked as though he was carrying a bow and arrow."

"I don't see anything," Rick said, shading his eyes.

Scotty squinted and then shook his head. "By golly, he was there, but he's gone now."

"We're probably the first white men the poor old sheepherder ever saw." Rick grinned. "Let him have his peek."

It was plain, as the days wore on, that Zircon was not pleased with the ruggedness of the going. He had expected narrow trails, he growled, but not rat runs. It seemed to Rick that every time they did come out upon a fairly usable trail, the map would indicate a turn and they would be back to clinging to the sides of the peaks.

Then, on the third Sunday of their journey, Scotty saw something again. He pointed behind him, but before Rick could hurry to his side, it was gone.

"It's a mirage," Rick laughed. "Only radar tramps like us would be silly enough to be found in this neck of the woods."

But Scotty kept turning his head to eye the rocks and the ledges behind him. Twice more he called to Rick to look to where he pointed. But neither time could Rick see the figure that Scotty said was there.

Then one day Sahmeed disengaged himself from the head of the caravan. As he walked back toward Zircon, he kept looking down into the valley from which they had just come. He stopped before the big scientist, beckoned him to the edge of the cliff and pointed far down and behind them.

Rick and Scotty hurried to his side and followed the giant's gaze. For a moment Rick could see nothing but dull, brown rock, then suddenly he gripped Scotty's arm. A streak of white had dodged from the shelter of a boulder and ran to the protection of another! It seemed tiny at this distance, but it was a figure, and one that obviously didn't want to be seen.

Zircon looked from Rick to Scotty and then said flatly: "We are being followed."

CHAPTER XII.

The Watchers

IMMEDIATELY after the white-clothed figure disappeared, Zircon ordered a double guard on their encampments. Rick, Scotty, and the professors alternated in watching over the sleeping camp. Scotty was sure that the white figure was not one of the figures he had seen previously. The other figures had not been dressed in white.

On the second night after the doubling of the guard, it was Scotty's turn to stand first watch. Rick was dog-tired from the day-long hike, and the moment he stretched out he was asleep. He had no idea how long he had slept or what woke him, but he found himself starting to sit up slowly, not knowing why he was doing it. Had he heard a sound?

He strained to see into the darkness.

Then Rick heard it! Scotty's low whistle - their private signal! Again it pierced the darkness and this time he located it, off to his right.

Grabbing his tiny flashlight, he scrambled barefoot across the loose rock, gritting his teeth in anguish at each noisy crunch. He almost fell over Scotty in the darkness and with a tremble in his voice whispered, "What is it?"

"I don't know," Scotty answered hoa.r.s.ely. "Sit here and watch."

Rick eased himself to a sitting position and stared in the direction Scotty had indicated. Little lights began to dance before his eyes as he tried to pierce the darkness.

For a full quarter hour they barely breathed as they waited for some betraying sound. Finally it came.

A sliding sound, then a ripping of cloth and a soft exclamation in the dark. Then quiet again.

"Over there," Scotty said, jabbing his finger toward the curve in the path.

Then they saw it. A white-clothed figure silhouetted against the sky.

"How did he get by the guard below?" Rick asked.

"That's probably his racket," Scotty whispered.

They watched the figure bob up and run behind a rock and then scamper closer to them.

"We are going to take this character with the old school tackle," Scotty whispered.

"You go high, I'll go low," Rick answered. They crouched together.

For a moment Rick feared that the figure had heard them, but it rose again and straightened up. Too far to attack yet, but then he saw a hand stealing into the white robe and his heart leaped into his throat. He had seen knives come out of such robes, and knew they could wait no longer.

Without a sound, Rick's legs buckled and in the next split second he and Scotty were flying through the air, straight for the figure in the darkness.

Scotty hit him at the neck and Rick tackled him squarely at the knees, and the figure bounced like a rubber ball. But their quarry wasn't giving up. Arms were flailing under the white robes and legs were kicking. In a flash, Scotty was astride the prostrate figure and pinioning the arms to the ground.

"The light!" he yelled to Rick.

Rick reached for his flashlight and flipped its switch. Then he turned its beam squarely into the face of the prowler beneath them.

There, staring up into their eyes was a face Rick had thought he was never to see again.

Chahda! It seemed unbelievable that the native boy could have managed to follow them all the way from Bombay, yet there he was. Rick and Scotty fired eager questions at him but it wasn't until later, over a good breakfast, that they heard the whole story.

Fully aware that all eyes were on him, Chahda sipped a cup of steaming tea slowly and with relish, deliberately prolonging the moment with his natural flair for the dramatic.

Rick grinned to himself as Scotty and the professors s.h.i.+fted uneasily. This, he thought, was Chahda's moment, and the Hindu boy intended to make the most of it.

At last Chahda put the teacup down and smiled at the faces around him.

"Very good tea,' he said politely.

Scotty exploded. "Come on! Can't you see we're waiting for you to tell us all about everything?"

Chahda settled himself comfortably. "Is like this?" He smiled at Rick. "You remember we talk about the map? How I say is not like what Sahibs in Nepal say?"

"I remember," Rick said.

"You not believing," Chahda accused. "I go away, so quiet no one see, and I go to the house of a Sikh. He is old man, this one. When I know him before, he is Risaldar-Major in Nepal."

"That's a rank in the British Colonial Cavalry," Weiss supplied.

"He know this Tibet good," Chahda continued. "I think, myself, he know about this map. But he is not home. I am sitted down on the stairs and wait. Such time pa.s.ses! But does this one go?" He waved his hand in an airy gesture. "Not Chahda! He waits some more."

"Go on, go on," Weiss said impatiently.

"Yes, Sahib. Soon comes the Sikh Sahib, and he is forget me, because I have new clothes, like a hazoor. But soon he remembers, and he shows me his maps of Tibet, and I show him the path from the maps.

"He looks and he makes great rumble in his beard, like so." Chahda demonstrated with a low growl. "He says: 'Ayah! Such a bad thing! How gets the Sahibs such a path?' And I say to him that is sent the maps by the Asiatic Geo ... Geo ..."

"Geographical Union," Rick said helpfully.

"Yes. He knows good those people. He takes me to them, and I show the path and they say they make no path like this on the maps for the Sahibs. They draw new on maps, and say, 'This is the path we draw.'

"My friend give me the new maps, and I am run for the station. But when I come, the train is go. I see Sahib Rick. I make shout, so loud! I make shout: 'Is wrong the maps!' Then the Van Groot Sahib is bang! I am dead. My new clothes is get dirt. Soon I am waking up." He paused dramatically. "Is gone the maps."

"Van Groot!" Scotty exclaimed. "If I ever get my hands on that walking cough drop I'll break his neck! He's behind all this. He must have switched maps. That's why he was so long bringing them."

"I'm afraid it looks that way, Scotty," Hobart Zircon agreed.

"But why?" Julius Weiss asked. "What could he hope to gain?"

Rick answered for all of them. "If we knew that ..." He stopped. "But we've said that before. Anyway, we know now that Van Groot is behind it. Van Groot and Conway, if there's any difference."

"But Van Groot's route should take us to the Tengi-Bu Plateau," Zircon mused.

"Are you sure of that, sir?" Rick asked. "He might have been sending us into a dead end of some kind."